Product Definition in Chemistry

Chemistry Glossary Definition of Product

A product is a new material formed in a chemical reaction.
A product is a new material formed in a chemical reaction. Comstock, Getty Images

Product Definition

In chemistry, a product is a substance that is formed as the result of a chemical reaction. In a reaction, starting materials called reactants interact with each other. After passing through a high energy transition state (achieving the activation energy for a reaction), the chemical bonds between the reactants are broken and rearranged to yield one or more products. 

When a chemical equation is written, reactants are listed on the left side, followed by the reaction arrow, and finally by products.

Products are always written on the right side of a reaction, even if it is reversible.

A + B → C + D

Where A and B are reactants and C and D are products.

In a chemical reaction, atoms are rearranged, but not created or destroyed. The number and type of atoms on the reactants side of the equation is the same as the number and type of atoms in the products.

The formation of products that are different from reactants is the difference between a chemical change and a physical change of matter. In a chemical change, the formulas of at least one of the reactants and products is different. For example, the physical change in which water melts into a liquid may be represented by the equation:

H2O(s) → H2O(l)

The chemical formulas of the reactants and products are the same.

Examples of Products

Silver chloride, AgCl (s), is the product of the reaction between the silver cation and chloride anion in aqueous solution:

Ag+ (aq) + Cl- (aq) → AgCl (s)

Nitrogen gas and hydrogen gas are the reactants that react to form ammonia as a product:

2 + 3H 2 → 2NH 3

The oxidation of propane yields the products carbon dioxide and water:

C3H8 + 5 O2 ® 3 CO2 + 4 H2O